JOHANNESBURG – Caster Semenya became the first South African to break through four minutes in the 1 500m at the Doha Diamond League meeting on Friday night, thumbing her nose at the IAAF’s new female eligibility rules.

It was a record-breaking night for the South African contingent, with short-sprint specialist Carina Horn also making history by breaking through the 11-second barrier.

She is the first local sprinter to dip below the magical mark, improving on the national mark she set at the South African championships in Pretoria in March.

Semenya smashed the national record she set at the Commonwealth Games last month, posting a winning time of 3:59.92.

The three-time world 800m champion has developed into a world-class three-and-three-quarter-lap runner since she won the bronze medal at last year’s global championships in London.

“I wanted to go faster, but had to slow down a little,” Semenya said. “It’s always been a dream to set the national record and continue to push beyond my personal best, and I think we definitely achieved what we came here for.

“I want to maintain this momentum throughout the season, but will also make sure I continue to keep healthy. My immediate next step is to go back and watch the race, and see where we can improve.”

Semenya held back over the first three laps before producing her characteristic kick with half a lap to go to crossing the line.

Kenya’s Nelly Jepkosgei finished in second place with 4:00.99, with Habitam Alemu of Ethiopia bagging the bronze in 4:01.41.

The IAAF announced its new controversial female classification rules last week, which would attempt to regulate women that naturally produce testosterone levels above five nanomoles per litre.

The regulations are limited to athletes who compete in events ranging from the 400m to the mile.

Semenya could be affected by the new regulations, which would go into effect on November 1.

The amended rules are expected to be challenged in the Court of Arbitration for Sport, with Athletics SA (ASA) announcing it would lobby the IAAF to drop the regulations or face action.

Horn raced to a new national record in the race immediately after Semenya won the 1 500m gold medal.

The Pretoria-based sprinter knocked 0.05 off her previous record, crossing the line in fifth place with a time of 10.98.

Horn shaved 0.03 off the 28-year-old record first set by Evette de Klerk back in 1990.

She was in fine form in a race that boasted a world-class field that included 200m world champion Dafne Schippers of the Netherlands and 100m-200m double silver medallist Marie-Josee Ta Lou of the Ivory Coast.

Horn finished ahead of Schippers, with Ta Lou winning with a world-leading time of 10.85.